A network device designed to forward packets to an external network such as the Internet. Most routers are used to direct traffic to a network outside of the one they reside in such as the Internet. However, when routers are used within an enterprise to keep subnetworks divided, they would just be called "routers" or possibly "core routers," but not WAN routers. The routers that make up the backbone of the Internet are known as "core routers." See router, core router and edge router.